Benralizumab

Benralizumab is a humanized afucosylated monoclonal antibody that targets the interleukin-5 receptor alpha (IL-5Rα) on eosinophils and basophils. By binding to IL-5Rα and engaging immune effector cells, it induces antibody-dependent cell-mediated cytotoxicity, leading to rapid depletion of eosinophils in blood and tissues. This mechanism addresses the eosinophilic inflammation that characterizes a subset of asthma.

Benralizumab is indicated as add-on maintenance therapy for adults and adolescents aged 12 years and older with severe eosinophilic asthma. It is intended to reduce exacerbations, improve lung function, and enhance asthma control in patients whose disease is driven by eosinophilic inflammation. The typical dosing regimen is 30 mg administered by subcutaneous injection every 4 weeks for the first three doses (weeks 0, 4, and 8), followed by injections every 8 weeks thereafter. Injections are administered by a healthcare professional in a clinic setting.

Clinical trials in adults and adolescents with severe eosinophilic asthma showed reductions in the rate of asthma exacerbations, improvements in lung function and symptom control, and, in some cases, reduced reliance on oral corticosteroids. Benefits are generally greater in patients with higher blood eosinophil counts prior to treatment.

Common adverse events include injection-site reactions, headache, fever, pharyngitis, and upper respiratory infections. Rare hypersensitivity reactions and anaphylaxis have been reported. Benralizumab causes sustained eosinophil depletion and may increase the risk of parasitic infections in endemic areas; patients should be evaluated accordingly. The drug is marketed as Fasenra and is administered by subcutaneous injection, usually in a clinical setting. It received regulatory approval in 2017 in the United States and/or Europe for its approved indication.